081  
FXUS66 KPDT 231751  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
951 AM PST TUE DEC 23 2025  
   
UPDATED AVIATION DISCUSSION...18Z TAFS
 
THE LOW STRATUS LAYER  
REMAINS LINGERING OVER KDLS UNTIL IT LIFTS AROUND THIS AFTERNOON.  
FOG HAS DEVELOPED IN PORTIONS OF THE COLUMBIA RIVER GORGE BUT NOT  
SO MUCH AT KDLS ITSELF, OBSERVED FROM THE WEBCAMS. HOWEVER, THE  
FOG SHOULD ALSO LIFT AS WELL AROUND THE SAME TIMEFRAME AS THE  
STRATUS LAYER WILL. OTHERWISE, THE REMAINING SITES IN VFR BEFORE  
FALL UNDER MVFR OR LOWER STARTING THIS AFTERNOON. THIS WILL  
DECREASE VSBYS AND/OR CIGS DUE TO THIS SYSTEM LEAVING BEHIND LOW  
CLOUDS AND MIST. KYKM MIGHT EVEN RECEIVE LIGHT RAIN/SNOW MIX  
OVERNIGHT WITH A 30% PROBABILITY. KALW MAY BE VFR LONGER THROUGH  
MOST OF TODAY, BUT COULD DROP TO IFR OVERNIGHT WHEN LOW CLOUDS  
ARRIVES ALONG WITH THE NEXT SYSTEM. KPSC WILL BE VFR THROUGH THIS  
TAF PERIOD, THOUGH LIGHT RAIN COULD DEVELOP AS THIS SYSTEM PASSES.  
FEASTER/97  
 

 
   
PREV DISCUSSION
 
/ISSUED 325 AM PST TUE DEC 23 2025/  
   
DISCUSSION
 
 
A WEAK SYSTEM WAS MOVING ACROSS THE CASCADES AND BRINGING SOME  
LIGHT SNOW TO THE AREA. THIS SYSTEM WILL WEAKEN BY AFTERNOON.  
THEN, SOME MOISTURE FROM THE SOUTHEAST WILL MOVE NORTHWESTWARD  
DURING THE AFTERNOON, AND WILL WEAKEN AS IT MOVES AND COULD  
TRIGGER SOME SHOWERS ALONG THE WAY.  
 
ON WEDNESDAY, MOISTURE FROM CALIFORNIA WILL MOVE NORTHWARD,  
HOWEVER, THE LATEST GUIDANCE HAS THE MAJORITY OF THIS MOISTURE  
STAYING TO OUR WEST AND EAST. SO WHILE THERE COULD DEFINITELY BE  
SOME PRECIPITATION, THE BEST CHANCES REMAIN IN THE IN THE  
MOUNTAINS AND OVERALL QPF IS LIGHT, AND MUCH OF THE AREA SHOULD BE  
DRY LATER WEDNESDAY INTO WEDNESDAY EVENING.  
 
AS LOW PRESSURE MOVES NORTHWARD OFF THE CALIFORNIA COAST TO OFF  
THE OREGON COAST LATER WEDNESDAY INTO THURSDAY, AND OTHER BATCH  
OF MOISTURE WILL ACCOMPANY IT. ONCE AGAIN, THERE WILL BRING SOME  
PRECIPITATION TO THE AREA, WITH THE BEST CHANCES OVER THE CASCADES  
AND LIGHT PRECIPITATION AND LOW (20-40 PERCENT) CHANCES  
ELSEWHERE. SOME PRECIPITATION CHANCES WILL LINGER INTO FRIDAY, AS  
THE UPPER LOW OFF THE COAST WEAKENS AND THE TROUGH MOVES INLAND  
BUT STAYS MAINLY SOUTH OF THE AREA.  
 
FINALLY, BY LATER FRIDAY INTO THE WEEKEND AND EARLY NEXT WEEK, A  
RIDGE WILL BUILD OVER THE PACIFIC NORTHWEST. THIS RIDGE WILL BRING  
DRY WEATHER AND NEAR NORMAL TEMPERATURES.  
 
ON WEDNESDAY, AS THE LOW APPROACHES, THE PRESSURE GRADIENT WILL  
TIGHTEN AND WINDS WILL INCREASE, ESPECIALLY OVER THE HIGHER  
TERRAIN. WINDS OF 15 TO 25 MPH WITH GUSTS 30 TO 35 MPH AND SOME  
LOCAL GUSTS TO 40 MPH ARE POSSIBLE. THE NBM PROBABILITIES OF WIND  
GUSTS >= 39 MPH ARE 50 TO 80 PERCENT FROM CENTRAL OREGON TO  
NORTHEASTERN OREGON. THE NBM PROBABILITIES OF WIND GUSTS >= 47  
MPH ARE 30 TO 60 PERCENT ACROSS THIS SAME AREA.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 45 34 50 35 / 60 40 30 20  
ALW 45 37 50 38 / 60 50 40 30  
PSC 43 35 48 32 / 40 60 30 20  
YKM 41 32 45 29 / 10 90 50 20  
HRI 43 35 49 33 / 50 60 30 20  
ELN 37 29 40 27 / 0 90 70 20  
RDM 43 31 50 29 / 50 40 30 10  
LGD 43 38 49 39 / 80 20 50 40  
GCD 48 40 51 36 / 90 20 60 40  
DLS 43 38 47 35 / 30 80 50 30  
 

 
   
PDT WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  

 
 

 
 
DISCUSSION...77  
AVIATION...97  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab OR Page
The Nexlab WA Page Main Text Page